The 23-year-old announced the surprise concert on Twitter on Saturday morning (13May17), telling his followers the gig would be taking place that night at The Garage in London.

"Hi, i'm playing a show in London tonight. Tickets are available now... See you later. H," he wrote, later following up the post with a poster for the gig.

Tickets were priced at just $12 (£10), were only available from the venue's box office, and limited to one ticket per person. All proceeds were donated to The Little Princess Trust, a charity close to Harry's heart after he donated his hair last year (16) to the organisation, which provides wigs to children experiencing hair loss.

Dressed in a pink satin Gucci suit with embroidered dragons, the One Direction star told the crowd: "This is my first show in a long time. My first show ever. So it's a night I won't forget. You might not be able to tell from my monotone voice, but I am having a great time."

Performing all the tracks from his debut solo album Harry Styles, including Sign of the Times and Carolina, the singer impressed the small but excited audience with his new solo style.

"I couldn’t ask for a better group of friends to have in this room tonight, thank you so much for being here, all of you," he said.

Harry also joked he had nearly knocked a fan out at a rehearsal for the gig after performing an unsuccessful stage dive. "Let me tell you,” he explained. “It doesn’t feel one third as cool as you think it does."

As well as his solo material, he also performed two covers - Kanye West’s track Ultralight Beam from his Life of Pablo album, and the One Direction track Stockholm Syndrome. "You may or may not know the words,” he joked to the screaming audience.

The singer even sang Happy Birthday to a fan at the front of his packed gig, and paused the show to check on one audience member who was struggling with the heat in the tiny venue.